Why dimples and soft spots occur in epoxy resin once cured?

Dimples or soft spots in epoxy resin can occur for several reasons, including:  Incomplete mixing: Properly mixing the epoxy resin and hardener is essential to ensure thorough dispersion and chemical reaction. Inadequate mixing can result in unmixed portions or inconsistent curing, leading to dimples or soft spots in the cured resin.  Insufficient curing time: Epoxy resin requires sufficient time to fully cure and harden. Rushing the curing process or not allowing the resin to cure for the recommended duration can result in incomplete curing, leading to soft spots or areas that remain tacky.  Incorrect resin-to-hardener ratio: Using an incorrect ratio of resin to hardener can cause curing issues. If the ratio is off, the resin may not cure properly, resulting in dimples or soft spots.  Environmental factors: Factors such as temperature and humidity can affect the curing process of epoxy resin. Extreme temperatures or high humidity can interfere with the resin’s ability to cure evenly and may contribute to the formation of dimples or soft spots.  Excessive thickness: Pouring epoxy resin in excessively thick layers can lead to excessive heat buildup during the curing process. This heat can cause uneven curing, resulting in dimples or soft spots. It is important to follow the manufacturer’s guidelines regarding the maximum recommended thickness or volume of resin to apply in a single pour.  Contamination or moisture: Contamination, such as dust or debris, or the presence of moisture on the surface or within the resin itself, can hinder the curing process. It can lead to areas where the resin does not cure properly, resulting in dimples or soft spots in the final cured surface.  To minimize the occurrence of dimples or soft spots in epoxy resin, it is crucial to carefully follow the manufacturer’s instructions regarding mixing ratios, curing times, and environmental conditions. Thoroughly mixing the resin and hardener, allowing sufficient curing time, and ensuring proper surface preparation are important steps to achieve a uniform and fully cured epoxy resin surface. Download PDF here